Study DesignRetrospective study.PurposeTo estimate the usefulness of bone scan and magnetic resonance imaging (MRI) for the diagnosis of new fracture in osteoporotic vertebral fractures.Overview of LiteratureThe diagnosis of new fractrure in osteoporotic vertebral fractures requires simple X-ray and supplementary studies.MethodsWe analyzed 87 vertebrae in 44 patients, who diagnosed with osteoporotic vertebral fractures using bone scan and MRI within 2 months interval between August 2001 and July 2008. We compared hot uptakes in bone scan with MRI findings such as new fractures, old fractures and degenerative lesions.ResultsHot uptakes in bone scan was matched to 48 new fractures, 26 old fractures and 13 degenerative lesions in MRI findings. It was 55% of concordance between hot uptakes in bone scan and new fractures in MRI. The rate of new vertebral fractures confirmed by MRI according to 1 level hot uptakes in bone scan was 96%, 2 levels was 50% and 3 more levels was 36%.ConclusionsThe diagnosis of new fracture in osteoporotic vertebral fractures requires simple X-ray and supplementary studies such as bone scan and MRI. We recommend more careful interpretation in multiple osteoporotic vertebral fracture patients about hot uptake lesions of bone scan.

To investigate the imaging features of synovial chondromatosis of the temporomandibular joint (TMJ), which is a rare benign arthropathy with cartilaginous proliferation.MATERIALS AND METHODS: Computed tomography and magnetic resonance imaging examinations of 34 patients with histopathologically confirmed primary synovial chondromatosis of the TMJ were reviewed retrospectively. Imaging features including the lesion epicentre, destruction/sclerosis of surrounding bone, calcification, periosteal reaction, osteophyte, lesion size, and joint space dimensions were assessed.RESULTS: Thirty-one of thirty-four patients (91.2%) showed the superior joint space as the lesion epicentre. For the mandibular condyle, more than one-third of patients (14/34; 41.2%) showed no destruction, and more than half of patients (19/34; 55.9%) showed no sclerosis. Conversely, >70% of patients showed destruction and sclerosis of the articular eminence/ glenoid fossa, while >80% of patients (28/34; 82.4%) presented with various calcifications, including the ring-and-arc (9/34; 26.5%) and popcorn (13/34; 38.2%) types. The mean joint space on the affected side was significantly larger than that of the unaffected side (p<0.001). More than three-fourths of patients (76.9%) experienced no interval increase in lesion size during an average of 1.6 years of follow-up.CONCLUSION: Synovial chondromatosis of the TMJ demonstrated several imaging features, including the lesion centre being located in the superior joint space, resultant articular eminence/glenoid fossa-oriented bone changes, ring-and-arc and popcorn calcification, joint space widening, and self-limiting growth. These imaging features may be helpful in differentiating synovial chondromatosis from other lesions of the TMJ.

To investigate the imaging features of chondrosarcoma of the temporomandibular joint (TMJ) and review the literature. MATERIALS AND METHODS: Computed tomography (CT), magnetic resonance imaging (MRI), and integrated positron-emission tomography (PET)/CT images of nine patients with histopathologically confirmed chondrosarcoma of the TMJ were reviewed retrospectively. Imaging features regarding the direction of lesion growth, bone destruction, infiltration into the tendon of the lateral pterygoid muscle (LPM) in the pterygoid fovea, enhancement pattern, calcification, periosteal reaction, markedly hyperintense T2 signal area, and qualitative PET signal intensity were evaluated. RESULTS: Seven of nine patients (77.8%) presented with lesion growth that was outward from the medulla of the mandibular condyle. Infiltration into the tendon of LPM in the pterygoid fovea was observed in all cases, and 77.8% (7/9) of them demonstrated >50% infiltration. All the lesions showed a mixed peripheral and internal enhancement, and revealed a markedly hyperintense T2 signal intensity area, which showed no enhancement. Although five of nine cases demonstrated higher FDG uptake compared with that of the liver, the other four cases showed less FDG uptake than that of the liver. CONCLUSION: Chondrosarcoma of the TMJ demonstrated several imaging features, including outward growth from the mandibular condyle, resultant infiltration into the tendon of LPM in the pterygoid fovea, various patterns of internal enhancement, and a markedly hyperintense T2 signal intensity area. These imaging features may be helpful to differentiate chondrosarcoma from other lesions of the TMJ.